Field of the Invention
The present invention relates to an air conditioner for a vehicle, and more particularly, to an air conditioner for a vehicle, which includes: a bypass passageway formed at a lower portion of an air-conditioning case which communicates with a desiccant part of a desiccant rotor and bypasses cold air and warm air passageways; a regeneration passageway formed at the lower portion of the air-conditioning case for supplying the air passing through the bypass passageway to a regeneration part of the desiccant rotor; and a heater having one side area arranged on the bypass passageway and the other side area arranged on the warm air passageway, so that the air conditioner heats the dehumidified air passing through the desiccant part of the desiccant rotor and the bypass passageway by the heater and supplies the heated air to the regeneration part of the desiccant rotor so as to regenerate the desiccant rotor.
Background Art
In general, an air conditioner for a vehicle is a car part, which is installed in a vehicle for the purpose of cooling or heating the interior of the vehicle in the summer season or the winter season or removing frost from a windshield in the rainy season or the winter season to thereby secure a driver's front and rear visual fields. Such an air conditioner typically includes a heating device and a cooling device together, so that it can heat, cool or ventilate the interior of the vehicle through the steps of selectively introducing the indoor air or the outdoor air into the air conditioner, heating or cooling the introduced air, and blowing the heated or cooled air into the vehicle.
According to mounted structures of an air blowing device unit, an evaporator unit and a heater core unit, such an air conditioner is classified into a three-piece type air conditioner where the air blowing device unit, the evaporator unit, and the heater core unit are disposed independently, a semi-center type air conditioner where the evaporator unit and the heater core unit are embedded in an air-conditioning case and the air blowing device unit is mounted separately, and a center-mounting type air conditioner where the three units are all embedded in the air-conditioning case.
Recently, an independent type air conditioner, which separately and independently provides air of different temperatures to a driver's seat and to a passenger's seat inside the vehicle to thereby individually heat and cool the seats according to the driver's or the passenger's need, has been disclosed.
FIG. 1 illustrates a conventional air conditioner for a vehicle. In FIG. 1, the air conditioner 1 includes: an air-conditioning case 10 having an air inflow port 11 formed at one side thereof and a defrost vent 12, a face vent 13 and floor vents 14 formed at the other side thereof in such a way as to be adjusted in degree of opening by mode doors 16; an evaporator 2 and a heater core 3 that are mounted on air passageways in the air-conditioning case 10 in order and spaced apart from each other at a predetermined interval; and an air blowing device 20 connected to the air inflow port 11 of the air-conditioning case 10 for sending indoor air or outdoor air.
Moreover, the air conditioner further includes a temperature-adjusting door 15 mounted between the evaporator 2 and the heater core 3 for controlling temperature by adjusting the degree of opening of a cold air passageway bypassing the heater core 3 and of a warm air passageway passing through the heater core 3.
Furthermore, the mode doors 16 control the degree of opening of the relevant vents and carry out various air discharge modes, namely, a vent mode, a bi-level mode, a floor mode, a mix mode, and a defrost mode.
As described above, in the air conditioner 1 for the vehicle, in case of the greatest cooling mode, the temperature-adjusting door 15 opens the cold air passageway and closes the warm air passageway. Therefore, the air blown by the air blowing device 20 heat-exchanges with refrigerant flowing inside the evaporator 2 while passing through the evaporator 2 and is converted into cold air. After that, the converted air is discharged to the inside of the vehicle through the vents opened by the mode doors 16 according to the predetermined air discharge mode namely, the vent mode, the bi-level mode, the floor mode, the mix mode, or the defrost mode, whereby the inside of the vehicle is cooled.
Moreover, in the case of the greatest heating mode, the temperature-adjusting door 15 closes the cold air passageway and opens the warm air passageway. Accordingly, the air blown by the air blowing device 20 passes through the evaporator 2, is converted into warm air by heat-exchanging with cooling water flowing inside the heater core 3 while passing through the heater core 3 through the warm air passageway. After that, the converted air is discharged to the inside of the vehicle through the vents opened by the mode door according to the predetermined air discharge mode, whereby the inside of the vehicle is heated.
In the air conditioner 1, the evaporator 2 cools the inside of the vehicle and provides a humidification action to remove moisture in the air discharged through the evaporator 2 when the surface temperature of the evaporator 2 falls below the dew point of the indoor air.
A cooling load of the evaporator 2 includes a sensible heat load related with a dry bulb temperature difference of the inflow air and a latent heat load related with a humidity difference. When the air conditioner is operated in a state where the outdoor air of high temperature and humidity flows indoors, the latent heat load out of the cooling load occupies most of the indoor space, and hence, the cooling efficiency is greatly lowered.
As described above, when the air conditioner is operated in the weather of high humidity, the air conditioner 1 is deteriorated in cooling efficiency due to an increase of the cooling load because moist air directly passes the evaporator 2, and if such an air flows to the inside of the vehicle in a cooled state after passing through the evaporator 2, comfort inside the vehicle is also deteriorated.
In order to solve the above problems, recently, an air conditioner in which a desiccant rotor 45 for dehumidification is mounted has been developed.
FIG. 2 is a block diagram of an air conditioner having the desiccant rotor. In brief, the conventional air conditioner having the desiccant rotor includes: a desiccant passageway 44 and a regeneration passageway 43 formed between an air blowing device 30 and an evaporator 41 of an air-conditioning case 40; a desiccant rotor 45 crossing over the desiccant passageway 44 and the regeneration passageway 43; and a regeneration heater 46 mounted inside the regeneration passageway 44 in front of the desiccant rotor 45.
In this instance, an outlet 44a of the regeneration passageway 44 extends in the outward direction of the vehicle, such that all of the air passing through the regeneration passageway 44 is discharged outside of the vehicle.
After that, if dehumidification is needed, the regeneration heater 46 is operated at the same time with rotation of the desiccant rotor 45.
Therefore, some of the air passing the air blowing device 30 flows to the evaporator 41 in a dehumidified state while passing the desiccant rotor 45 located in the desiccant passageway 43. After that, the air is cooled while passing through the evaporator 41, selectively passes through a heater core 42, and then, is supplied to the inside of the vehicle.
The remaining air passing the air blowing device 30 is flown into the regeneration passageway 44, and then, passes the desiccant rotor 45 located in the regeneration passageway 44 in a state where it is heated by the regeneration heater 46.
In this instance, because the desiccant rotor 45 rotates toward the regeneration passageway 44 in a state where it absorbs moisture in the desiccant passageway 43, the air heated by the regeneration heater 46 forces the moisture absorbed by the desiccant rotor 45 to evaporate while passing the desiccant rotor 45, and then, is discharged out through the outlet 44a of the regeneration passageway 44.
Through the above-mentioned process, the surface of the desiccant rotor 45 regenerates to its original dried condition so as to have the dehumidification capacity.
However, the conventional air conditioner has several problems in that the number of components is increased and the entire size of the air conditioner is also increased because the regeneration heater 46 must be installed in order to regenerate the desiccant rotor 45.
Moreover, because the air used for regeneration of the desiccant rotor 45 is unconditionally discharged out, the air-conditioning performance is lowered due to a decrease of air volume, and the conventional air conditioner is ineffective and has many difficulties in improving heating performance since lots of energy is abandoned during the heating mode.
Furthermore, the conventional air conditioner has another problem in that it is difficult to provide a pleasant environment to the inside of the vehicle because it cannot carry out an air-conditioning mode, such as ventilation inside the vehicle.